| Millennium: | 3rd Millennium BC |
|---|---|
| Centuries: | 28th cent. BC – 27th cent. BC – 26th cent. BC |
| Decades: | 2670s BC 2660s BC 2650s BC – 2640s BC – 2630s BC 2620s BC 2610s BC |
| Years: | 2649 BC 2648 BC 2647 BC – 2646 BC – 2645 BC 2644 BC 2643 BC |
| Gregorian calendar | 2646 MMDCXLVI |
| Ab urbe condita | 3399 |
| Armenian calendar | 2095 ԹՎ ՍՂԵ |
| Assyrian calendar | 7396 |
| Bahá'í calendar | 802–803 |
| Bengali calendar | 2053 |
| Berber calendar | 3596 |
| British Regnal year | N/A |
| Buddhist calendar | 3190 |
| Burmese calendar | 2008 |
| Byzantine calendar | 8154–8155 |
| Chinese calendar | 乙丑年 (Wood Ox) 5342 or 5282 — to — 丙寅年 (Fire Tiger) 5343 or 5283 |
| Coptic calendar | 2362–2363 |
| Discordian calendar | 3812 |
| Ethiopian calendar | 2638–2639 |
| Hebrew calendar | 6406–6407 |
| Hindu calendars | |
| - Vikram Samvat | 2702–2703 |
| - Shaka Samvat | 2567–2568 |
| - Kali Yuga | 5746–5747 |
| Holocene calendar | 12646 |
| Igbo calendar | 1646–1647 |
| Iranian calendar | 2024–2025 |
| Islamic calendar | 2086–2087 |
| Japanese calendar | Heisei 658 (平成６５８年) |
| Javanese calendar | 2598–2599 |
| Juche calendar | 735 |
| Julian calendar | Gregorian minus 18 days |
| Korean calendar | 4979 |
| Minguo calendar | ROC 735 民國735年 |
| Nanakshahi calendar | 1178 |
| Thai solar calendar | 3189 |
| Unix time | 21332505600–21364041599 |
The year 2646 BC